ELEVATED INTERLEUKIN-8 CONCENTRATIONS IN AMNIOTIC-FLUID OF MOTHERS WHOSE NEONATES SUBSEQUENTLY DEVELOP BRONCHOPULMONARY DYSPLASIA

Objective: To determine if an intrauterine sub-clinical inflammatory p rocess is a risk factor for the development of bronchopulmonary dyspla sia. Methods: A cohort study was conducted in patients who met the fol lowing criteria: (1) Singleton gestation; (2) preterm labor or preterm premature rupture of the membranes, (3) amniocentesis for microbiolog ic studies of the amniotic fluid and (41 delivery between 24 and 28 we eks of gestation. Bronchopulmonary dysplasia was defined as the need f or supplemental oxygen fur 78 days or longer after birth, associated w ith compatible chest radiographic findings. Amniotic fluid interleukin -8, was measured using a specific immunoassay. Logistic regression ana lysis and bootstrap procedure were used for statistical purposes. Resu lts: Forty-seven patients met the inclusion criteria for this study. A mong these patients, the prevalence of bronchopulmonary dysplasia was 23.4% (11/47). Amniotic fluid culture was positive in 21 out of 47 (44 .7%) patients. Median (range) amniotic fluid interleukin-8 concentrati on was higher in patients whose neonates subsequently developed bronch opulmonary dysplasia than in those who did not (17 [9.8-583.7] ng ml(- 1) versus 9.6 [0.91-744] ng ml(-1), P = 0.057). An amniotic fluid IL-8 level greater than 11.5 ng ml(-1) was far more common in mothers whos e fetuses went on to develop bronchopulmonary dysplasia than in those who did not (10/11 [90.9%] versus 17/36 [47%]; P = 0.01). This relatio nship remained significant even after correcting for the effect of ges tational age and birthweight (Odds ratio: 11.9; P < 0.05), Conclusion: Sub-clinical intrauterine inflammation is a risk factor for the subse quent development of bronchopulmonary dysplasia. We propose that in ut ero aspiration of fluid with high concentration of pro-inflammatory me diators may contribute to the lune injury responsible for the developm ent of bronchopulmonary dysplasia. (C) 1998 Elsevier Science ireland L td.